#define JEMALLOC_BASE_C_
#include "jemalloc/internal/jemalloc_preamble.h"
#include "jemalloc/internal/jemalloc_internal_includes.h"
#include "jemalloc/internal/assert.h"
#include "jemalloc/internal/extent_mmap.h"
#include "jemalloc/internal/mutex.h"
#include "jemalloc/internal/sz.h"
/******************************************************************************/
/* Data. */
static base_t *b0;
metadata_thp_mode_t opt_metadata_thp = METADATA_THP_DEFAULT;
const char *metadata_thp_mode_names[] = {
"disabled",
"auto",
"always"
};
/******************************************************************************/
static inline bool
metadata_thp_madvise(void) {
return (metadata_thp_enabled() &&
(init_system_thp_mode == thp_mode_default));
}
static void *
base_map(tsdn_t *tsdn, extent_hooks_t *extent_hooks, unsigned ind, size_t size) {
void *addr;
bool zero = true;
bool commit = true;
/* Use huge page sizes and alignment regardless of opt_metadata_thp. */
assert(size == HUGEPAGE_CEILING(size));
size_t alignment = HUGEPAGE;
if (extent_hooks == &extent_hooks_default) {
addr = extent_alloc_mmap(NULL, size, alignment, &zero, &commit);
} else {
/* No arena context as we are creating new arenas. */
tsd_t *tsd = tsdn_null(tsdn) ? tsd_fetch() : tsdn_tsd(tsdn);
pre_reentrancy(tsd, NULL);
addr = extent_hooks->alloc(extent_hooks, NULL, size, alignment,
&zero, &commit, ind);
post_reentrancy(tsd);
}
return addr;
}
static void
base_unmap(tsdn_t *tsdn, extent_hooks_t *extent_hooks, unsigned ind, void *addr,
size_t size) {
/*
* Cascade through dalloc, decommit, purge_forced, and purge_lazy,
* stopping at first success. This cascade is performed for consistency
* with the cascade in extent_dalloc_wrapper() because an application's
* custom hooks may not support e.g. dalloc. This function is only ever
* called as a side effect of arena destruction, so although it might
* seem pointless to do anything besides dalloc here, the application
* may in fact want the end state of all associated virtual memory to be
* in some consistent-but-allocated state.
*/
if (extent_hooks == &extent_hooks_default) {
if (!extent_dalloc_mmap(addr, size)) {
goto label_done;
}
if (!pages_decommit(addr, size)) {
goto label_done;
}
if (!pages_purge_forced(addr, size)) {
goto label_done;
}
if (!pages_purge_lazy(addr, size)) {
goto label_done;
}
/* Nothing worked. This should never happen. */
not_reached();
} else {
tsd_t *tsd = tsdn_null(tsdn) ? tsd_fetch() : tsdn_tsd(tsdn);
pre_reentrancy(tsd, NULL);
if (extent_hooks->dalloc != NULL &&
!extent_hooks->dalloc(extent_hooks, addr, size, true,
ind)) {
goto label_post_reentrancy;
}
if (extent_hooks->decommit != NULL &&
!extent_hooks->decommit(extent_hooks, addr, size, 0, size,
ind)) {
goto label_post_reentrancy;
}
if (extent_hooks->purge_forced != NULL &&
!extent_hooks->purge_forced(extent_hooks, addr, size, 0,
size, ind)) {
goto label_post_reentrancy;
}
if (extent_hooks->purge_lazy != NULL &&
!extent_hooks->purge_lazy(extent_hooks, addr, size, 0, size,
ind)) {
goto label_post_reentrancy;
}
/* Nothing worked. That's the application's problem. */
label_post_reentrancy:
post_reentrancy(tsd);
}
label_done:
if (metadata_thp_madvise()) {
/* Set NOHUGEPAGE after unmap to avoid kernel defrag. */
assert(((uintptr_t)addr & HUGEPAGE_MASK) == 0 &&
(size & HUGEPAGE_MASK) == 0);
pages_nohuge(addr, size);
}
}
static void
base_extent_init(size_t *extent_sn_next, extent_t *extent, void *addr,
size_t size) {
size_t sn;
sn = *extent_sn_next;
(*extent_sn_next)++;
extent_binit(extent, addr, size, sn);
}
static size_t
base_get_num_blocks(base_t *base, bool with_new_block) {
base_block_t *b = base->blocks;
assert(b != NULL);
size_t n_blocks = with_new_block ? 2 : 1;
while (b->next != NULL) {
n_blocks++;
b = b->next;
}
return n_blocks;
}
static void
base_auto_thp_switch(tsdn_t *tsdn, base_t *base) {
assert(opt_metadata_thp == metadata_thp_auto);
malloc_mutex_assert_owner(tsdn, &base->mtx);
if (base->auto_thp_switched) {
return;
}
/* Called when adding a new block. */
bool should_switch;
if (base_ind_get(base) != 0) {
should_switch = (base_get_num_blocks(base, true) ==
BASE_AUTO_THP_THRESHOLD);
} else {
should_switch = (base_get_num_blocks(base, true) ==
BASE_AUTO_THP_THRESHOLD_A0);
}
if (!should_switch) {
return;
}
base->auto_thp_switched = true;
assert(!config_stats || base->n_thp == 0);
/* Make the initial blocks THP lazily. */
base_block_t *block = base->blocks;
while (block != NULL) {
assert((block->size & HUGEPAGE_MASK) == 0);
pages_huge(block, block->size);
if (config_stats) {
base->n_thp += HUGEPAGE_CEILING(block->size -
extent_bsize_get(&block->extent)) >> LG_HUGEPAGE;
}
block = block->next;
assert(block == NULL || (base_ind_get(base) == 0));
}
}
static void *
base_extent_bump_alloc_helper(extent_t *extent, size_t *gap_size, size_t size,
size_t alignment) {
void *ret;
assert(alignment == ALIGNMENT_CEILING(alignment, QUANTUM));
assert(size == ALIGNMENT_CEILING(size, alignment));
*gap_size = ALIGNMENT_CEILING((uintptr_t)extent_addr_get(extent),
alignment) - (uintptr_t)extent_addr_get(extent);
ret = (void *)((uintptr_t)extent_addr_get(extent) + *gap_size);
assert(extent_bsize_get(extent) >= *gap_size + size);
extent_binit(extent, (void *)((uintptr_t)extent_addr_get(extent) +
*gap_size + size), extent_bsize_get(extent) - *gap_size - size,
extent_sn_get(extent));
return ret;
}
static void
base_extent_bump_alloc_post(base_t *base, extent_t *extent, size_t gap_size,
void *addr, size_t size) {
if (extent_bsize_get(extent) > 0) {
/*
* Compute the index for the largest size class that does not
* exceed extent's size.
*/
szind_t index_floor =
sz_size2index(extent_bsize_get(extent) + 1) - 1;
extent_heap_insert(&base->avail[index_floor], extent);
}
if (config_stats) {
base->allocated += size;
/*
* Add one PAGE to base_resident for every page boundary that is
* crossed by the new allocation. Adjust n_thp similarly when
* metadata_thp is enabled.
*/
base->resident += PAGE_CEILING((uintptr_t)addr + size) -
PAGE_CEILING((uintptr_t)addr - gap_size);
assert(base->allocated <= base->resident);
assert(base->resident <= base->mapped);
if (metadata_thp_madvise() && (opt_metadata_thp ==
metadata_thp_always || base->auto_thp_switched)) {
base->n_thp += (HUGEPAGE_CEILING((uintptr_t)addr + size)
- HUGEPAGE_CEILING((uintptr_t)addr - gap_size)) >>
LG_HUGEPAGE;
assert(base->mapped >= base->n_thp << LG_HUGEPAGE);
}
}
}
static void *
base_extent_bump_alloc(base_t *base, extent_t *extent, size_t size,
size_t alignment) {
void *ret;
size_t gap_size;
ret = base_extent_bump_alloc_helper(extent, &gap_size, size, alignment);
base_extent_bump_alloc_post(base, extent, gap_size, ret, size);
return ret;
}
/*
* Allocate a block of virtual memory that is large enough to start with a
* base_block_t header, followed by an object of specified size and alignment.
* On success a pointer to the initialized base_block_t header is returned.
*/
static base_block_t *
base_block_alloc(tsdn_t *tsdn, base_t *base, extent_hooks_t *extent_hooks,
unsigned ind, pszind_t *pind_last, size_t *extent_sn_next, size_t size,
size_t alignment) {
alignment = ALIGNMENT_CEILING(alignment, QUANTUM);
size_t usize = ALIGNMENT_CEILING(size, alignment);
size_t header_size = sizeof(base_block_t);
size_t gap_size = ALIGNMENT_CEILING(header_size, alignment) -
header_size;
/*
* Create increasingly larger blocks in order to limit the total number
* of disjoint virtual memory ranges. Choose the next size in the page
* size class series (skipping size classes that are not a multiple of
* HUGEPAGE), or a size large enough to satisfy the requested size and
* alignment, whichever is larger.
*/
size_t min_block_size = HUGEPAGE_CEILING(sz_psz2u(header_size + gap_size
+ usize));
pszind_t pind_next = (*pind_last + 1 < sz_psz2ind(SC_LARGE_MAXCLASS)) ?
*pind_last + 1 : *pind_last;
size_t next_block_size = HUGEPAGE_CEILING(sz_pind2sz(pind_next));
size_t block_size = (min_block_size > next_block_size) ? min_block_size
: next_block_size;
base_block_t *block = (base_block_t *)base_map(tsdn, extent_hooks, ind,
block_size);
if (block == NULL) {
return NULL;
}
if (metadata_thp_madvise()) {
void *addr = (void *)block;
assert(((uintptr_t)addr & HUGEPAGE_MASK) == 0 &&
(block_size & HUGEPAGE_MASK) == 0);
if (opt_metadata_thp == metadata_thp_always) {
pages_huge(addr, block_size);
} else if (opt_metadata_thp == metadata_thp_auto &&
base != NULL) {
/* base != NULL indicates this is not a new base. */
malloc_mutex_lock(tsdn, &base->mtx);
base_auto_thp_switch(tsdn, base);
if (base->auto_thp_switched) {
pages_huge(addr, block_size);
}
malloc_mutex_unlock(tsdn, &base->mtx);
}
}
*pind_last = sz_psz2ind(block_size);
block->size = block_size;
block->next = NULL;
assert(block_size >= header_size);
base_extent_init(extent_sn_next, &block->extent,
(void *)((uintptr_t)block + header_size), block_size - header_size);
return block;
}
/*
* Allocate an extent that is at least as large as specified size, with
* specified alignment.
*/
static extent_t *
base_extent_alloc(tsdn_t *tsdn, base_t *base, size_t size, size_t alignment) {
malloc_mutex_assert_owner(tsdn, &base->mtx);
extent_hooks_t *extent_hooks = base_extent_hooks_get(base);
/*
* Drop mutex during base_block_alloc(), because an extent hook will be
* called.
*/
malloc_mutex_unlock(tsdn, &base->mtx);
base_block_t *block = base_block_alloc(tsdn, base, extent_hooks,
base_ind_get(base), &base->pind_last, &base->extent_sn_next, size,
alignment);
malloc_mutex_lock(tsdn, &base->mtx);
if (block == NULL) {
return NULL;
}
block->next = base->blocks;
base->blocks = block;
if (config_stats) {
base->allocated += sizeof(base_block_t);
base->resident += PAGE_CEILING(sizeof(base_block_t));
base->mapped += block->size;
if (metadata_thp_madvise() &&
!(opt_metadata_thp == metadata_thp_auto
&& !base->auto_thp_switched)) {
assert(base->n_thp > 0);
base->n_thp += HUGEPAGE_CEILING(sizeof(base_block_t)) >>
LG_HUGEPAGE;
}
assert(base->allocated <= base->resident);
assert(base->resident <= base->mapped);
assert(base->n_thp << LG_HUGEPAGE <= base->mapped);
}
return &block->extent;
}
base_t *
b0get(void) {
return b0;
}
base_t *
base_new(tsdn_t *tsdn, unsigned ind, extent_hooks_t *extent_hooks) {
pszind_t pind_last = 0;
size_t extent_sn_next = 0;
base_block_t *block = base_block_alloc(tsdn, NULL, extent_hooks, ind,
&pind_last, &extent_sn_next, sizeof(base_t), QUANTUM);
if (block == NULL) {
return NULL;
}
size_t gap_size;
size_t base_alignment = CACHELINE;
size_t base_size = ALIGNMENT_CEILING(sizeof(base_t), base_alignment);
base_t *base = (base_t *)base_extent_bump_alloc_helper(&block->extent,
&gap_size, base_size, base_alignment);
base->ind = ind;
atomic_store_p(&base->extent_hooks, extent_hooks, ATOMIC_RELAXED);
if (malloc_mutex_init(&base->mtx, "base", WITNESS_RANK_BASE,
malloc_mutex_rank_exclusive)) {
base_unmap(tsdn, extent_hooks, ind, block, block->size);
return NULL;
}
base->pind_last = pind_last;
base->extent_sn_next = extent_sn_next;
base->blocks = block;
base->auto_thp_switched = false;
for (szind_t i = 0; i < SC_NSIZES; i++) {
extent_heap_new(&base->avail[i]);
}
if (config_stats) {
base->allocated = sizeof(base_block_t);
base->resident = PAGE_CEILING(sizeof(base_block_t));
base->mapped = block->size;
base->n_thp = (opt_metadata_thp == metadata_thp_always) &&
metadata_thp_madvise() ? HUGEPAGE_CEILING(sizeof(base_block_t))
>> LG_HUGEPAGE : 0;
assert(base->allocated <= base->resident);
assert(base->resident <= base->mapped);
assert(base->n_thp << LG_HUGEPAGE <= base->mapped);
}
base_extent_bump_alloc_post(base, &block->extent, gap_size, base,
base_size);
return base;
}
void
base_delete(tsdn_t *tsdn, base_t *base) {
extent_hooks_t *extent_hooks = base_extent_hooks_get(base);
base_block_t *next = base->blocks;
do {
base_block_t *block = next;
next = block->next;
base_unmap(tsdn, extent_hooks, base_ind_get(base), block,
block->size);
} while (next != NULL);
}
extent_hooks_t *
base_extent_hooks_get(base_t *base) {
return (extent_hooks_t *)atomic_load_p(&base->extent_hooks,
ATOMIC_ACQUIRE);
}
extent_hooks_t *
base_extent_hooks_set(base_t *base, extent_hooks_t *extent_hooks) {
extent_hooks_t *old_extent_hooks = base_extent_hooks_get(base);
atomic_store_p(&base->extent_hooks, extent_hooks, ATOMIC_RELEASE);
return old_extent_hooks;
}
static void *
base_alloc_impl(tsdn_t *tsdn, base_t *base, size_t size, size_t alignment,
size_t *esn) {
alignment = QUANTUM_CEILING(alignment);
size_t usize = ALIGNMENT_CEILING(size, alignment);
size_t asize = usize + alignment - QUANTUM;
extent_t *extent = NULL;
malloc_mutex_lock(tsdn, &base->mtx);
for (szind_t i = sz_size2index(asize); i < SC_NSIZES; i++) {
extent = extent_heap_remove_first(&base->avail[i]);
if (extent != NULL) {
/* Use existing space. */
break;
}
}
if (extent == NULL) {
/* Try to allocate more space. */
extent = base_extent_alloc(tsdn, base, usize, alignment);
}
void *ret;
if (extent == NULL) {
ret = NULL;
goto label_return;
}
ret = base_extent_bump_alloc(base, extent, usize, alignment);
if (esn != NULL) {
*esn = extent_sn_get(extent);
}
label_return:
malloc_mutex_unlock(tsdn, &base->mtx);
return ret;
}
/*
* base_alloc() returns zeroed memory, which is always demand-zeroed for the
* auto arenas, in order to make multi-page sparse data structures such as radix
* tree nodes efficient with respect to physical memory usage. Upon success a
* pointer to at least size bytes with specified alignment is returned. Note
* that size is rounded up to the nearest multiple of alignment to avoid false
* sharing.
*/
void *
base_alloc(tsdn_t *tsdn, base_t *base, size_t size, size_t alignment) {
return base_alloc_impl(tsdn, base, size, alignment, NULL);
}
extent_t *
base_alloc_extent(tsdn_t *tsdn, base_t *base) {
size_t esn;
extent_t *extent = base_alloc_impl(tsdn, base, sizeof(extent_t),
CACHELINE, &esn);
if (extent == NULL) {
return NULL;
}
extent_esn_set(extent, esn);
return extent;
}
void
base_stats_get(tsdn_t *tsdn, base_t *base, size_t *allocated, size_t *resident,
size_t *mapped, size_t *n_thp) {
cassert(config_stats);
malloc_mutex_lock(tsdn, &base->mtx);
assert(base->allocated <= base->resident);
assert(base->resident <= base->mapped);
*allocated = base->allocated;
*resident = base->resident;
*mapped = base->mapped;
*n_thp = base->n_thp;
malloc_mutex_unlock(tsdn, &base->mtx);
}
void
base_prefork(tsdn_t *tsdn, base_t *base) {
malloc_mutex_prefork(tsdn, &base->mtx);
}
void
base_postfork_parent(tsdn_t *tsdn, base_t *base) {
malloc_mutex_postfork_parent(tsdn, &base->mtx);
}
void
base_postfork_child(tsdn_t *tsdn, base_t *base) {
malloc_mutex_postfork_child(tsdn, &base->mtx);
}
bool
base_boot(tsdn_t *tsdn) {
b0 = base_new(tsdn, 0, (extent_hooks_t *)&extent_hooks_default);
return (b0 == NULL);
}